Patients with chronic hemolysis due to defects in production of reduced glutathione or reduced nucleotides are being treated with large doses of vitamin E. It is postulated that vitamin E can act as a free radical scavenger and provide a partial protective effect against oxidative related hemolysis in this group of patients. Red cell survival pre- and post-therapy, as well as routine hematologic parameters and clinical course, are being monitored to evaluate the efficacy of this therapeutic approach. A large clinical trial of high dose vitamin E therapy has been completed in Greek Mediterranean type glucose-6-phosphate dehydrogenase deficient subjects. A second study in 46 patients from Beersheba, Israel with mediterroneon type G6PD deficiency was initiated. An additional 8 patients with sever chronic hemolysis due to G6PD deficiency have been entered into a study at the NIH.